Page end indicator



April 8, 1958 s. B. TIBBLI'NG 5 9 PAGE END INDICATOR Filed Dec. 30, 1954 2 Sheets-Sheet 1 INVENTOR.

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ATTORNEY April 8, 1958. s. B. TIBBLING PAGE END INDICATOR 2 Sheets-Sheet 2 Filed D90. 30, 1954 F IG.3

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STIG B TlBBLlNG ATTORNEY- United States Patent PAGE END INDICATOR Sfig B. Tibbling, Hyde Park, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application December 30, 1954, Serial No. 478,614

2 Claims. (Cl. 197-189) ent that it is advantageous to provide a device for indicating the last line to be typed on a sheet thereby assuring proper composition of printed matter relative to the page. Accordingly, it is a first object of this invention to provide an improved page end indicator for use with a typewriter.

It is a further object of this invention to provide an improved page end indicator which may be readily attached to a typewriter without the use of skilled labor.

It is a further object of this invention to provide an improved page end indicator which is operable with typing sheets of varying lengths.

It is a still further object of this invention to provide an improved page end indicator having over-running means which will not block the operation of a platen when the typing field has been completed, and which indicator is automatically resettable to a pre-selected start position at the will of the operator.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is aperspective view of the improved page end indicator.

Fig. 2 is an end view of the elements in the page end indicator in one position.

Fig. 3 is an end view of the same elements in a second position.

Fig. 4 is a section view taken through plane 4-4 of Fig. 2; while Fig. 5 is a front elevation of the dial rotated to its Fig. 3 position.

Briefly, this invention relates to a clip-on page end indicator which may be readily attached to the cover of a typewriter carriage. The page end indicator, which has a driving gear spring biased into engagement with a platen gear, is provided with integral means for permitting the platen gear to run free of the indicator driving gear after the latter has reached a predetermined position. The page end indicator is further provided with adjustable means so that it will operate for sheets having typing field lengths varying from four to fourteen inches.

In the drawings, a typewriter carriage 2 is shown having a platen 4 and an end cover 6 comprising an upper portion 8 and a lower portion 10, hingedly connected at their rear joint 12. The improved page end indicator 16, the subject matter of this invention, is mounted by means of a spring clip 18 on the lower half 10 of the end cover 6. Basically, the clip 18 is provided with a bent over finger 20 having a U-shape for hooking onto the platen shaft aperture 21 in the bottom portion 10 of the cover 6; and with a plurality of spring clip fingers 24, 26 and 28 for gripping other portions of the bottom portion 10 of cover 6 thereby removably mounting the clip 18, and conse quently the indicator 16 (as later described), on the cover 6.

In order to drive the page end indicator, the platen shaft 22 is provided with a gear, for example, the gear 30, which is secured to and rotatable with the platen shaft 22 thereby acting as'a rotation responsive device. The gear 30 may be either a separate item bushed onto the shaft 22, or in a preferred embodiment, in order to facilitate field installation, an activator 29 comprising a unitary platen handle 32, bushing 34 and gear 30 is provided, which activator is slid onto the platen shaft 22 to replace the conventional platen handle.

The indicator 16 itself, which is pivotally mounted on a stud 36 carried by the spring clip 18, comprises a supporting arm 38, a housing 40, a setting knob or button 42 including a pointer 44 for adjusting the length of the page to be handled, a driving gear 46, and suitable interconnecting mechanism. Basically, the driving gear 46 is rotatably mounted co-axially of setting button 42. More specifically, the setting button 42, as viewed in Fig. 4, has an integral shaft 48 defining a threaded axial aperture or bore 50. The driving gear 46 has a central bushing 52 including a bearing 53 which fits over the shaft 48 and is held co-axially of, and free for rotation relative to, the shaft 48 by a screw 54 which passes through a retaining washer 55 into the threaded bore 50.

The setting button 42 has an inner clip member 56 which embraces a groove 57 in the hub 59 of the button 42 so that the button 42 and clip 56 are rotatable in unison; one member being on the outside, and the other being on the inside of housing 40. The clip 56 has an integral detent arm 58 including a spring detent 60 engageable with internal teeth 62 provided on the inner side of the housing 40. The spring detent 60 is in alignment with the pointer44 carried by the setting knob 42 except that the detent 60 is inside the housing 40, while pointer 44 is outside. The clip 56 also has an integral tail piece 64 which is approximately displaced from the detent 60. The tail piece 64 acts as a stop to limit the rotation of driving gear 46 in a clockwise direction as shown by the inter-engagement of a gear stop 66 carried by driving gear 46 and the tail piece 64 as viewed in Fig. 2. The housing 40 is also provided on its inner surface with a fixed stop 68 which will limit the counterclockwise rotation of the driving gear 46 by engaging the gear stop 66 to the extent shown in Fig. 3.

A spring 70 is spirally wound between the planes of the driving gear 46 and the housing 40, and interconnects the detent arm 58 and the gear 46 in such a manner that the gear is biased clockwise to its Fig. 2 position wherein the gear stop 66 engages the tail piece 64. Since the tail piece 64 is fixedly connected to the setting knob 42, it is obvious that by turning the knob 42 clockwise from its position shown in Fig. 2, the driving gear, as controlled by the inter-engagement of its stop 66 with tail piece 64, will rotate clockwise to increase its arc of counterclockwise travel from tail piece 64 to fixed stop 68. Similarly, if the indicating knob 42 is turned counterclockwise from the position shown in Fig. 2, the distance between the tail piece 64 and the fixed stop is decreased so that there will be a lesser are negotiated by the indicating gear 46 in moving from the tail piece 64 to the fixed stop 68. It is apparent that with this mechanism, the maximum and minimum length of typing page for which this page end indicator is operable is determined by the possible degree of rotation of the setting knob 42 in moving the tail piece 64 relative to the fixed stop 68.

It will be noted in Fig. 3 that when the gear stop 66 engages the fixed stop 68, a peripheral portion 71 of gear 46 Patented'Apr. 8, 1958 will be in engagement with the gear 30 carried by the platen shaft 22. The peripheral portion 71 is recessed to permit the platen gear 30 to rotate in the recessed peripheral portion 71 free of the driving gear 46. This structure provides for the free movement of the platen shaft 22 after the driving gear has moved to its Fig. 3 position, This position of the driving gear is reached when the last line of a typing field reaches printing position.

It will be noted that the spring clip 18 is provided with an integral spring arm 72 which acts on the arm 38 of the indicator to urge the housing 4-0 of the indicator counterclockwise about the supporting stud 36 (as viewed in Fig. 3) thereby holding driving gear 46 in driving engagement with the platen gear 30. This resilient inter-engagement of platen gear 39 and driving gear 46 assures rotation of the driving gear 45 in response to advancement of the typing field with the platen. The spring arm 7 2 is provided adjacent its outer end with a hook 73 which will engage a complementary shoulder 75 on housing 40 when the latter has been rocked clockwise to disengaging position thereby holding driving gear 46 disengaged from platen gear 30.

Operation In operation, as soon as the housing 40 is pivoted clockwise (as viewed in Fig. 3) about supporting stud 36 to an extent that the driving gear 46 is disengaged from the platen gear 30, the driving gear 46 will be rotated to its clockwise limit as viewed in 'Fig. 2; This clockwise limit is adjustable in response to movement of knob 42.

Assuming that a page of predetermined typing. field length was at its first printing line at the time that the housing has been rocked away from the platen gear 30, then the driving gear will be at its adjustable rest (i. e. stop 66 engaging tail piece 64) position, and the indicator will be operable, when the gear 46 is re-engaged with platen gear 30, to move counterclockwise towards its Fig. 3 position in response to advancement of the page with the platen.

Accordingly, by marking numbers on a dial 74, which is an integral part of gear 46, and assuming a zero spot on the dial 74 is to appear opposite the pointer 76 when the last line of a typing field is in printing position (see Fig. the operator can judge the amount of writing space left on the page being typed. The dial 74 is graduated from zero up to fourteen so as to handle-a typing field varying from four to fourteen inches. Depending on the setting of knob 42, a corresponding number between 4 and 14 will be opposite the pointer 76 every time the driving gear 46 is reset to its Fig. 2 position. The dial 74 reading will diminish towards its zero or Fig. 5 reading as the lines of the printing field are advanced.

While there has been shown and described and pointed out the fundamental novel features of the invention, as applied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a typewriter having a carriage including a platen, a device for indicating the relative rotation of the platen comprising a driving portion operable in response to the rotation of said platen, and an indicating portion, said indicating portion comprising an arm pivotally supported on said carriage to be swingable toward and away from said driving portion, resilient means biasing said arm normally toward said driving portion, an indicating dial rotatably supported on said arm, and means driving said dial in response to the operation of said driving portion while said arm is in its biased position thereby to indicate the relative rotation of said platen, said dial driving means having a spring biasing said dial normally in one direction, an adjustable stop .for varying the limit of rotation of said dial in said biased direction, and a fixed stop for limiting the rotation of said dial in the opposite direction, said dial driving means further having a recessed portion proximate said driving portion when said dial is stopped by said fixed stop thereby automatically disengaging said dial driving means from driving relation withsaid driving portion while said arm is in its biased position.

2. In a typewriter having a movable carriage including a platen rotatably supported on the carriage, a device for indicating the relative rotation of said platen and hence the corresponding length of writing field of a sheet supported on said platen comprising a driving portion mounted on said carriage frame to be movable in response to the rotation of said platen, and an indicating portion comprising a base, an arm pivotally supported on said base to be swingable toward and away from said driving portion, integral spring clip means positioned on said base for holding the same on said typewriter carriage, resilient means for biasing said arm into engagement with said driving portion, an indicating dial rotatably supported on said arm, and means driving said dial in response to the operation of said driving portion while said arm is in its biased position, said dial driving means having a spring biasing the same normally in one direction, an adjustable stop for limiting the movement of said dial in biased direction, and a fixed stop for limiting the movement of said dial in the opposite direction, said dial driving means further having provision while said arm is in its biased position for being disengaged automatically from said driving portion when the movement of said dial has been interrupted by said fixed stop.

References Cited in the file of this patent UNITED STATES PATENTS 1,175,410 Corcoran Mar; 14, 1916 1,332,632 Paddock Mar. 2, 1920 2,212,463 Thomas Aug. 20, 1940 

